Method of curing or vulcanizing rubber goods.



FATBNTED MAR. 17, w08.

` M 382ML 0. L. PEPBR.

MT50@ o? .uname 0R vJLGANIzING RUBBER Gama APPLIUATIQS Him; 5211215,loos.

ma, fr@ mrtowegf @f2 l No, 882,341.

CHARLES L. PEPPER, OF INDIANAPOLIS, INDIANA METHOD OF CURING ORVULCANIZIN G RUBBER GOODS.

Specification of Letters Patent.

Patentedmarch 17, .1908.

Application filed Sentember'l, 1906. Serial No. 334,791.

To all wfvmI it may concern:

. Be itknown that I, CHARLES L. PEPPER,

alcitize'n of the United States, 'residing in olis, Marion county,Indiana, have Indiana V invente a new` and useful Improvement in Methods`of Curing or Vulcanizmg Rubber p ordinary procedure heretofore in thevulcani-yy zatlon of suchtlre shoes or casings has been of which thefollowing is a specification.

.This invention relates to methods of curing or vulcanizing rubbergoods, and particularlyk to the vulcaniz'ation of the outer shoes orcasings for pneumatic tires.

The primary object of the invention is to provide an improved method ofvulcanizing molded rubber goods by the direct action of heated vgas orvapor, preferablysteam, without danger of distortion of the goods duringthe vulcanization process; and va special ol5`ect of the invention as itrelates to the vulcanization of the outer shoes or casings for pneumatictires is to provide for vthe complete vulcanization of a tire shoe orcasing y means of a' single exposure of the tire shoeor casiiig to theaction gas orvapor. A

Owing to the peculiar\structure of the shoes or casings for pneumatictires, the

of the heated to place the yunvulcanized tire shoe upon a core or formand inclose the tire shoe so supported in a mold which is then subjectedto eat and pressure. This procedure is not entirely satisfactory as therubber vulcanized in this Way is not so well adapted to withstand wearas rubber which is cured or vulcanized in an open heat by the directaction of steam or some other heated gas or vapor. In order to Asecurethe increased durability which characterizes rubber vulcanized in anopen heat the p'ractice has arisen of first vulcanizing a carcass for atire shoe in a mold, then cementiug on the exterior of `thisvulcanizedcarcass a tread of unvulcanized rubber, and the tire with its supportingcore is then rovided with a porous wrapping of textile abrio andsubjected to the action of steam or other heated oras or vapor n'i anopen heat to effect the vu canization of the tread. The results of thismethod are not entirely satisfactory because portions of the tire areapt to become over cured by being exposed twice to the vulcanizing heatand when the other portions of the tire are not over cured by thismethod the tread-is apt to be only partially cured i and not adated'toVwithstand the wear to which it is su jected. y l

Inv carrying out my invention I make use of a core upon which the tireshoe or casing is supported, suitable clampin rings for securing themarginal portions'o the tire in position and a orous covering forV thetread portion of t e tire. These elements are illustrated in threeslightly dierent forms in the `accompanying drawings forming wart ofthis specification, in which correspon( ing parts are designated bysimilar characters of reference in the several views.

In the drawings: Figure 1 is a sectional f perspective View of a portionof one form of apparatus employed, showing a section of tire suitablyheld by the apparatus and ready for vulcanization. Fig. 2 1s a sectionalperspective view similar to Fig. l but showing a slightly different formof apparatus. Fig'. 3 is a small transverse sectional view showing athird form ofy apparatus with the tire secured in position thereby.

Stated in general terms the method which forms the present inventionconsists simply.

in supporting the unvulcanized tire shoe or casing in form, applying aorous covering of textile fabric or its equiva ent over the treadportion of the tire shoe or casing and exposmg the tire so supported andcovered to tho action of heated gas or vaporin a suitable vulcanizingchamber. When apparatus of the character illustrated in Fig. 1 isemployed the unvulcanized tire shoe T is mounted on the core 1 whichisof annular form and may be collapsible or not, as desired. A covering2 of textile fabric out on the bias is applied circumferentially to thetread portion kof the tire shoe or casing as shown, the' bias fabricconforming readily to the shape of the tire and lying in close contacttherewith. Clam ing members 3 are applied to hold the tire siioe in formupon the core and to hold the marginal portions of the porous covering2in position upon the tread of the tire shoe. These clamping members 3are preferably annular, thou h they may be made in section if desiree?,and are secured in engagement with the tire by any suitable means, as bymeans of`transverse bolts 4 extending `through lugs 5 provided on theclamping members for that The apparatus i ust/rated in Fig. 2 differsfrom that shown in Fig. 1 in havin the cover for the tread of the tireappliedI after the clamping members are brought into engageplurpose.'

` tire shoe.. -After`the`l clamping members 3EL bolts 4 or the 'thetread'of the tire shoewhich is exposed bel which it Adiffers simply inthe amount of the outer surface of the tire shoe which is covered fbe'rs3a. This covering 2a consists simply of "a long strip of bias fabricwhich is wound around the tire shoe and the clamping memlbers 3a inoverlapping Whorls or turns substantially transverse tothe tread of thetire "is applied over the tread and side portions of -ing members 3Cwhich. extend beyond ment' with the tire shoe and core. In thisl rubberof the tread portion of the tire is exfigure the tire shoe is vfirst vInoiir'ited on a core, then clan'ip'ing members` 3 areemployed to secureAthe tire shoe position. These clamping members are beveled on theirouter surfaces so as to -taper sharply toward their. outer edges andpresent surfaces 3b' which are substantially tangential to thetread ofthe .are secured in osition by means of clamping e,a covering 2,a isapplied to tween the outer edges of the clamping memshoe. i

Ther apparatus illustrated in Fig. 3 very closely resembles that vshownin Fig. 1,-from by the porous covering. The tire shoe having beenmounted onthe'core, a covering 2b the, tire show, this covering beingformed of fabric cut bias and wound circumferentially aroundjthe `tireshoe', but being of such width that it e ends downwardupon the sides ad-In a'tire of t upon which it is secured by means of clamp# t e clencheredges or beads only to a suiiicient distance to secure the -tire'shoeiirmly upon thecore 1.

When apparatus ofany one of the three forms above describedandllustrated in the drawings is emplo ed, the tire suitably clamped'and' rovi ed over its tread, and, perhaps over t e side portions aswell, is in troduced into a vulcanizing chamber and there subjected tothe action of the heated Steam under pressure is gen` erally regarded asthe best medium for transmitting the heat and thispenetrates the porouscovering of textile fabric so that the but it will be obvious that whenthe tire shoe is to be cured according to this invention the entire shoeis constructed of 'raw' uncured stock and the tread applied at the timeof construction. The tire is then vulcanized as Aan entirety in a singleoperation, thus obviating the necessity of first vulcanizing the carcassand then vulcanizing the tread portion subsequently.

Having thus described my inyention, what I claim as new and desiretosecureby Let'- ters Patents is:

1. The method of vulcanizing or curing' the outer shoes or casings forpneumatic tires for vehicles, which consists in supportin and securingthe slice or casing in form, app ying a porous cover to the exposedsdrface of the shoe or casing, and subjecting the shoeor casing sosupported and covered to the ac. tion of vulcanizing heat.

2. The method of vulcanizing or curing the outer sheaths or casings forpneumatic tires for vehicles which consists in supporting the shoe orcasing upon a core, clamping the shoe or casing in position on the corewith the tread portion exposed, placing a porous cov- 'erlng' over theexposed surfaces of the t1re s hoe or casing and in contact therewith,and subjecting the shoe or casing so su ported, clamped and covered tothe action o vulcan.-

izing heat. j

' In testimony whereof, l have signed my name in the presence of twowitnesses.

CHARLES L. PEPPER... Witnesses:

yC. H. SEMPLE,

G. H. HAMILTON.

